June 21, 2018—KB4284863 (Preview of Monthly Rollup)

Applies to: Windows 8.1Windows Server 2012 R2

Improvements and fixes


This nonsecurity update includes improvements and fixes that were a part of KB 4284815 (released June 12, 2018) and also includes these new quality improvements as a preview of the next Monthly Rollup update:

  • Updates the Universal CRT to achieve parity with the Windows 10 Universal CRT build 10.0.14393.0.
  • Addresses encoding issue with the Bitcoin symbol. 
  • Addresses an issue in which SmartHeap doesn't work with UCRT. 
  • Addresses an issue that sometimes prevents eDrives from unlocking when an eDrive is a secondary drive and the system drive is protected with BitLocker. 
  • Addresses an issue in dfsutil.exe that occurs when exporting a DFS namespace as an XML file. The issue occurs when the namespace contains a link with a target that points to a shared folder that has an "&" character in its name. As a result, the generated XML doesn't correctly escape the "&" character, and dfsutil.exe cannot export the namespace. 
  • Addresses an issue where a clustered SMB server may become unresponsive in certain conditions when under a high workload. 
  • Addresses an issue in a Remote Desktop VDI deployment that prevents a mounted UPD from disconnecting, which results in the creation of temp files. 
  • Addresses an issue where the user profile service leaks a token handle. Token leaks on computers that install MS16-111 (KB3175024) intentionally consume a session. Token and session leaks, in sufficient volume, can degrade device performance and reliability with increased system uptime. This is especially true on RDP and Kiosk computers that have a large number of user logons.
  • Addresses an issue in which the Universal CRT cannot output Japanese characters by using the putwchar function and std::cout/std::wcout objects.

Known issues in this update


Microsoft is not currently aware of any issues in this update.

How to get this update


This is provided as an Optional update on Windows Update. For more information about how to run Windows Update, see How to get an update through Windows Update. To get the standalone package for this update, go to the Microsoft Update Catalog website.

File information

For a list of the files that are provided in this update, download the file information for update 4284863